Search

CN-224231129-U - Piezoresistive and capacitive composite sensor

CN224231129UCN 224231129 UCN224231129 UCN 224231129UCN-224231129-U

Abstract

The utility model relates to a piezoresistive capacitive composite sensor which comprises a sensing array, a piezoresistive measuring circuit, a capacitance-digital conversion circuit, a switch array and a processing module. Each measuring point in the sensing array is provided with a piezoresistive material which is split to form an insulation interval, the piezoresistive material of each measuring point is correspondingly provided with a first electrode and a second electrode, the first electrode is multiplexed to serve as a capacitance sensing electrode, the second electrode serves as a near ground end of the measuring point, a gating switch is connected in series between the second electrode and the ground, the piezoresistive measuring circuit is respectively coupled with the first electrode and the second electrode of each point through the switch array, the capacitance digital conversion circuit is respectively coupled with the first electrode of each point through the switch array, and the processing module is respectively coupled with the piezoresistive measuring circuit and the capacitance digital conversion circuit to control the on-off of each switch. The sensor has simple and compact structure, high spatial resolution and high sensitivity.

Inventors

  • SUN TENGCHEN
  • ZHANG DAHUA
  • ZENG FANYOU

Assignees

  • 北京他山科技有限公司

Dates

Publication Date
20260512
Application Date
20250530

Claims (8)

  1. 1. A piezoresistive capacitive composite sensor is characterized in that: The device comprises a measuring branch, a switch array, a processing module and at least two measuring points; Each measuring point is arranged to form a sensing array, each measuring point in the sensing array is used for detecting the spatial position of a stressed acting point of the sensor, each measuring point is provided with a piezoresistive material, the piezoresistive material between each measuring point or between the collection areas formed by a plurality of measuring points is divided to form an insulation interval, the piezoresistive material of each measuring point is correspondingly provided with a first electrode and a second electrode, the first electrode and the second electrode are respectively arranged on the upper surface and the lower surface of the piezoresistive material, the first electrode is positioned on the top surface of the piezoresistive material and is multiplexed to serve as a capacitance sensing electrode, the second electrode serves as the near-ground end of the measuring point, and a gating switch is connected in series between the second electrode and the ground; The measuring branch circuit comprises a piezoresistance measuring circuit and a capacitance-digital conversion circuit, wherein the piezoresistance measuring circuit is respectively coupled with a first electrode and a second electrode of each point location through a switch array and is used for acquiring piezoresistance signals between the first electrode and the second electrode on each point location when an object is in contact, and the capacitance-digital conversion circuit is respectively coupled with the first electrode of each point location through the switch array and is used for acquiring self capacitance of the first electrode and/or mutual capacitance between two mutually insulated first electrodes when the object is close; The processing module is respectively coupled with the piezoresistance measuring circuit and the capacitance-digital conversion circuit and controls the on-off of each switch.
  2. 2. The piezoresistive capacitive composite sensor according to claim 1, characterized in that: The first electrodes and the second electrodes are strip electrodes, the first electrodes are arranged at a certain interval along the transverse direction, the second electrodes are arranged at a certain interval along the longitudinal direction, so that a determinant staggered lattice is formed in the vertical projection direction, and the staggered position is used as the measuring point.
  3. 3. The piezoresistive capacitive composite sensor according to claim 1, characterized in that: the first electrode and the second electrode of each measuring point are point electrodes, each first electrode is arranged above the piezoresistive material in an array, and each second electrode is arranged below the piezoresistive material in an array Fang Paibu.
  4. 4. The piezoresistive capacitive composite sensor according to claim 1, characterized in that: The first electrodes of the measuring points are point electrodes, and the first electrodes are arranged in an array; The second electrodes of the measurement points in the same collection area are integrally formed into a single common electrode, and the point electrodes are positioned above the common electrode.
  5. 5. A piezoresistive capacitive composite sensor is characterized in that: The device comprises a measuring branch, a switch array, a processing module and at least two measuring points; Each measuring point is arranged to form a sensing array, each measuring point in the sensing array is used for detecting the spatial position of a stressed acting point of the sensor, each measuring point is provided with a piezoresistive material, the piezoresistive material between each measuring point or between the collection areas formed by a plurality of measuring points is divided to form an insulation interval, the piezoresistive material of each measuring point is correspondingly provided with a first electrode and a second electrode, the first electrode and the second electrode are arranged on the piezoresistive material in a coplanar manner, the first electrode is multiplexed to be used as a capacitance sensing electrode, the second electrode is used as the near-ground end of the measuring point, and a gating switch is connected in series between the second electrode and the ground; The measuring branch circuit comprises a piezoresistance measuring circuit and a capacitance-digital conversion circuit, wherein the piezoresistance measuring circuit is respectively coupled with a first electrode and a second electrode of each point location through a switch array and is used for acquiring piezoresistance signals between the first electrode and the second electrode on each point location when an object is in contact, and the capacitance-digital conversion circuit is respectively coupled with the first electrode of each point location through the switch array and is used for acquiring self capacitance of the first electrode and/or mutual capacitance between two mutually insulated first electrodes when the object is close; The processing module is respectively coupled with the piezoresistance measuring circuit and the capacitance-digital conversion circuit and controls the on-off of each switch.
  6. 6. The piezoresistive capacitive composite sensor according to claim 5, characterized in that: The first electrode and the second electrode of each measuring point are point electrodes, and the first electrode and the second electrode are commonly positioned above the piezoresistive material and are arranged into an array.
  7. 7. The piezoresistive capacitive composite sensor according to claim 1 or 5, characterized in that: the first electrode and/or the second electrode is a flexible electrode.
  8. 8. The piezoresistive capacitive composite sensor according to claim 1 or 5, characterized in that: The measuring point has at least three, and the switch array is configured to allow any at least two first electrodes to be selectively combined to form a pair of electrode groups for detecting mutual capacitance and/or to selectively connect any at least two first electrodes in parallel to form a large electrode with increased area.

Description

Piezoresistive and capacitive composite sensor Technical Field The utility model relates to machine touch perception, in particular to a piezoresistive and capacitive composite sensor. Background In the task that the robot performs fine operation or dynamically interacts with the environment, surface touch sensing and proximity sensing are two key capabilities, the surface touch sensing detects pressure distribution on the surface of an object, the common scene has control force when grabbing objects, motion stops immediately after collision, non-contact detection realizes sensing the distance, azimuth and motion trend of surrounding objects before non-contact, and the common scene has obstacle avoidance or pre-grabbing planning. CN113970395B proposes a flexible sensing array with contact and non-contact, which includes an interdigital electrode packaging layer, an interdigital electrode substrate layer, a capacitance isolation layer, a piezoresistive top electrode layer, a porous piezoresistive material layer and a piezoresistive bottom electrode layer which are sequentially stacked from top to bottom, and is essentially that the capacitance sensor and the piezoresistive sensor are stacked up and down, although dual-mode integration can be realized, the piezoresistive layer needs to deform to detect pressure, after stacking, the pressure is absorbed by the packaging and substrate parts of the capacitance electrode, and the problems of delayed touch response, low sensitivity and the like exist. CN210036760U proposes a dual-mode sensor of capacitance and piezoresistance, where a transmitting electrode, a piezoresistance sensitive layer and a conducting electrode form a piezoresistance sensor, a receiving electrode is additionally arranged beside the transmitting electrode, and the transmitting electrode multiplexing and the receiving electrode form a capacitive sensor, so as to achieve dual-mode multiplexing, but the surface touch realizes fine force distribution detection by piezoresistance units needing dense distribution, and the side-arranged receiving electrode is difficult to consider high spatial resolution, and meanwhile, increases difficulty for leads. Disclosure of utility model In order to overcome the defects in the prior art, the utility model provides a piezoresistive capacitive composite sensor. The piezoresistive-capacitive composite sensor structure comprises a measuring branch, a switch array, a processing module and at least two measuring points, wherein each measuring point in the sensing array is arranged to form a sensing array, each measuring point is used for detecting the spatial position of a stressed acting point of a sensor, each measuring point is provided with a piezoresistive material, the piezoresistive material between the measuring points or between a collection area formed by a plurality of measuring points is divided into an insulating interval, the piezoresistive material of each measuring point is correspondingly provided with a first electrode and a second electrode, the first electrode and the second electrode are respectively arranged on the upper surface and the lower surface of the piezoresistive material, the first electrode is positioned on the top surface of the piezoresistive material and multiplexed to serve as a capacitance sensing electrode, the second electrode serves as the near end of the measuring point, a gating switch is connected in series between the second electrode and the ground, the piezoresistive measuring branch comprises a piezoresistive measuring circuit and a capacitance digital conversion circuit, the piezoresistive measuring circuit is respectively coupled with the first electrode and the second electrode of each point through the switch array, the piezoresistive digital conversion circuit is used for acquiring a piezoresistive signal between the first electrode and the second electrode when the object contacts, the capacitance digital conversion circuit is respectively coupled with each first electrode and the first electrode through the switch array, and the capacitance digital conversion circuit is used for respectively controlling the mutual capacitance and mutual capacitance or mutual capacitance conversion between the first electrode and the two capacitance conversion circuit. Further, the first electrodes and the second electrodes are strip-shaped electrodes, the first electrodes are arranged at a certain interval along the transverse direction, the second electrodes are arranged at a certain interval along the longitudinal direction, so that a determinant staggered lattice is formed in the vertical projection direction, and the staggered positions are used as measuring points. Further, the first electrode and the second electrode of each measuring point are point electrodes, each first electrode is arranged above the piezoresistive material in an array, and each second electrode is arranged below the piezoresistive material in an ar